The present invention relates to a new and improved method of forming a cast metal article which contains a cavity.
Many different cast metal articles have been formed with an internal cavity. To form the internal cavity, a core may be positioned in a mold and molten metal poured around the core. After the molten metal has solidified to form a cast metal article, the core is removed from the cast metal article. Removal of the core from the cast metal article leaves a cavity in the cast metal article.
In the past, cores have been removed from cast metal articles by exposing the cores to a leaching liquid. To facilitate the removal of cores from cast metal articles, various systems have been proposed to increase the efficiency with which a leaching liquid is utilized. Some of these systems are disclosed in U.S. Pat. Nos. 3,563,711; 3,694,264; and 5,332,023 and in U.S. Published Patent Application No. 2010/0000700. However, difficulty is still encountered in removing cores, particularly ceramic cores, from cast metal articles.